diff --git a/get-shit-done/bin/lib/model-profiles.cjs b/get-shit-done/bin/lib/model-profiles.cjs
index 64105ffe2..ae3472148 100644
--- a/get-shit-done/bin/lib/model-profiles.cjs
+++ b/get-shit-done/bin/lib/model-profiles.cjs
@@ -26,7 +26,7 @@ const MODEL_PROFILES = {
   'gsd-doc-writer': { quality: 'opus', balanced: 'sonnet', budget: 'haiku', adaptive: 'sonnet' },
   'gsd-doc-verifier': { quality: 'sonnet', balanced: 'sonnet', budget: 'haiku', adaptive: 'haiku' },
 };
-const VALID_PROFILES = Object.keys(MODEL_PROFILES['gsd-planner']);
+const VALID_PROFILES = [...Object.keys(MODEL_PROFILES['gsd-planner']), 'inherit'];
 
 /**
  * Formats the agent-to-model mapping as a human-readable table (in string format).
@@ -58,7 +58,9 @@ function formatAgentToModelMapAsTable(agentToModelMap) {
 function getAgentToModelMapForProfile(normalizedProfile) {
   const agentToModelMap = {};
   for (const [agent, profileToModelMap] of Object.entries(MODEL_PROFILES)) {
-    agentToModelMap[agent] = profileToModelMap[normalizedProfile];
+    agentToModelMap[agent] = normalizedProfile === 'inherit'
+      ? 'inherit'
+      : profileToModelMap[normalizedProfile];
   }
   return agentToModelMap;
 }
diff --git a/tests/bug-2601-inherit-model-profile.test.cjs b/tests/bug-2601-inherit-model-profile.test.cjs
new file mode 100644
index 000000000..c80234784
--- /dev/null
+++ b/tests/bug-2601-inherit-model-profile.test.cjs
@@ -0,0 +1,49 @@
+'use strict';
+
+/**
+ * Regression tests for bug #2601
+ *
+ * `config-set-model-profile inherit` (and `config-set model_profile inherit`)
+ * was rejected by the validator even though the runtime accepts 'inherit' as a
+ * valid model_profile value meaning "inherit from parent configuration".
+ *
+ * Root cause: VALID_PROFILES in model-profiles.cjs is derived from
+ * Object.keys(MODEL_PROFILES['gsd-planner']), which does not include 'inherit'.
+ * cmdConfigSetModelProfile() rejects any value not in VALID_PROFILES.
+ */
+
+const { describe, test } = require('node:test');
+const assert = require('node:assert/strict');
+const { runGsdTools, createTempProject, cleanup } = require('./helpers.cjs');
+
+describe('bug #2601: config-set-model-profile accepts inherit', () => {
+  test('config-set-model-profile inherit succeeds', (t) => {
+    const tmpDir = createTempProject();
+    t.after(() => cleanup(tmpDir));
+    const result = runGsdTools(['config-set-model-profile', 'inherit'], tmpDir);
+    assert.ok(result.success, `should accept inherit: ${result.error}`);
+  });
+
+  test('config-set model_profile inherit succeeds', (t) => {
+    const tmpDir = createTempProject();
+    t.after(() => cleanup(tmpDir));
+    const result = runGsdTools(['config-set', 'model_profile', 'inherit'], tmpDir);
+    assert.ok(result.success, `config-set model_profile inherit should succeed: ${result.error}`);
+  });
+
+  test('config-set-model-profile inherit writes inherit to config', (t) => {
+    const tmpDir = createTempProject();
+    t.after(() => cleanup(tmpDir));
+    runGsdTools(['config-set-model-profile', 'inherit'], tmpDir);
+    const getResult = runGsdTools(['config-get', 'model_profile'], tmpDir);
+    assert.ok(getResult.success, `config-get should succeed: ${getResult.error}`);
+    assert.strictEqual(JSON.parse(getResult.output), 'inherit');
+  });
+
+  test('config-set-model-profile still rejects truly invalid profiles', (t) => {
+    const tmpDir = createTempProject();
+    t.after(() => cleanup(tmpDir));
+    const result = runGsdTools(['config-set-model-profile', 'not-a-real-profile'], tmpDir);
+    assert.ok(!result.success, 'should reject invalid profiles');
+  });
+});
diff --git a/tests/model-profiles.test.cjs b/tests/model-profiles.test.cjs
index 03d36f7d7..ca06fa9f7 100644
--- a/tests/model-profiles.test.cjs
+++ b/tests/model-profiles.test.cjs
@@ -65,13 +65,16 @@ describe('MODEL_PROFILES', () => {
 // ─── VALID_PROFILES ───────────────────────────────────────────────────────────
 
 describe('VALID_PROFILES', () => {
-  test('contains quality, balanced, and budget', () => {
-    assert.deepStrictEqual(VALID_PROFILES.sort(), ['adaptive', 'balanced', 'budget', 'quality']);
+  test('contains quality, balanced, budget, adaptive, and inherit', () => {
+    assert.deepStrictEqual(VALID_PROFILES.sort(), ['adaptive', 'balanced', 'budget', 'inherit', 'quality']);
   });
 
-  test('is derived from MODEL_PROFILES keys', () => {
+  test('includes all MODEL_PROFILES keys plus inherit', () => {
     const fromData = Object.keys(MODEL_PROFILES['gsd-planner']);
-    assert.deepStrictEqual(VALID_PROFILES.sort(), fromData.sort());
+    for (const profile of fromData) {
+      assert.ok(VALID_PROFILES.includes(profile), `VALID_PROFILES should include ${profile}`);
+    }
+    assert.ok(VALID_PROFILES.includes('inherit'), 'VALID_PROFILES should include inherit');
   });
 });